Gasoline manufacture with byproduct recovery



R. M. ISHAM E T A1. 2,145,025

GASOLIUE MANUFACTURE WITH BY-PRODUUT RECOVERY Jan 24, 1939.`

Original Filed Oct.- 30.. 1923 Sheets-Sheet Jan. 24, 1939. R. M. lsHAME-r AL 2,145,025

GASOLINE ANUFACTURE WITH BY-PRODUGT RECOVERY Original Filed Oct. 30,1923 2 Sheets-Sheet 2 Patented Jan. 24, 1939 UNITED; STATES 4G'AsonuvaMANUFACTURE wrm BY- Paonuc'r RECOVERY Robert M. Isham, Okmulgee, Okla.,and Henry N. Lyons, Maplewood, N. J., assignors, by mesne assignments,to Power Patents Company, Jersey City, N. J., a corporation of MaineApplication October 30, 1923,

Serial No. 671,645

Renewed December 18, 1935 38 Claims.

Our invention relates primarily to the production of gasoline and ofalkyl sulphates.

The production of cracked gasoline as commonly practiced heretofore hasinvolved a careful and expensive chemical treatment of the distillateincluding theuse of sulphuric acid followed by redistillation to obtaina. product having the desired characteristics. The distillate soobtained by the ordinary process has not, however, been suitable for usefor blending with straightrun or uncracked gasoline without one or moreredistillations.

It is also known to treat the tail gas from the cracking stills withsulphuric acid in the presence of an inert menstruum such as gas oil toform mixed alkyl sulphatesfnthe mixture consisting principally of acidalkyl sulphates. These sulphates are afterward hydrolyzed to producealcohols.

It is the principal object ci our invention to so combine the productionof cracked gasoline and alkyl sulphates so as to improve the process ofproducing cracked gasoline and the product itself as well as the processof producing alkyl sulphates. A

Other objects and advantages of our invention will appear to thoseskilled in the art from the following description taken with theaccompanying drawings in which Fig. 1 is a diagrammatic view of anapparatus according to our invention adapted to carry out our improvedprocess;

Fig. 2 is an elevation of the acid absorption apparatus shown in Fig. l.r

In thedrawings 4 is a still which may be of an convenient type ofpressure still having an inlet B for oil to be treated and a vaporoutlet through pipe 8. The boiling point of the oil forming the rawmaterial of the present process is relatively high compared to theboiling point of the product K y obtained in greatest volume, suchproduct being motor spirit or gasoline material. Still 4 is normallyheated to a temperature high enough to crack the oil being fed in at 6by rieans of a ame in furnace l0. Cracked vapors passing out of still 4by line 8 enter a dephlegmator i2 wherein certain of the heavy vaporsare condensed'and flow back into still 4 through a trapped line I4.`

'I'he still 4 is preferably so operated that the vapors leaving the topof the dephlegmator I2 have a temperature of about 520 F. Vapors leavethe upper part'of dephlegmator l2 through pipe I 6 having a pressurereducing valve i8 therein, the pipe I6 leading' to a condenser coil 20.The valve 'I8 may be so adjusted that the pressure in the condensingcoil 20 is reduced substantially to atmospheric. uid in the tank 22surrounding the coil 20 is maintained at such a temperature that thecoil itself is normally between 135 F. and 150 F. when o p- According toour invention the liq- (Cl. 26o- 460) erating at atmospheric pressure.From coil 20 liquid and uncondensed gases pass by pipe 24 to a separatortank 26 wherein pressure benzine separates from the vapors and gases andis taken oi through pipe 28. The uncondensed vapors andy gases iiow outof the tank 26 by pipe 30 to a comprcssor 32 which is connected by pipe34 to a cooling coil 36.v The pressure produced by compressor 32preferably is so related to the temperature in the cooling coil 36 thatthe ordinary gasoline material, as well as unsaturated hydrocarbons suchas amylene and higher olenes areA con- ,densed in coil 36. From thecooling coil 36 the liquids and gases pass by pipe 38 to a reactiontower 40 within which the gasoline and uncondensed gases flow upwardlyin contact with a down-coming stream of concentrated sulphuric acidintroduced into the upper end of tower 40 by pipe 42. In case, however,it is desired to operate condenser 20 under pressure valves 3l and 33 inpipes 30 and 34 respectively are closed, valve i8 is opened and thegases and vaporspassed directly from separator tank 26 through pipe 36,pipe 35, valve 31 and pipe 34 to cooler 36. Moreover, the pressure onthe gas and condensed Vapors entering the absorber may only be thatnecessary to force this material through tower 40. This, of course,varies with the height of the tower. f 4

In the processes which have been used heretofore a large loss lhas beenencountered, due to the polymerization of the oleilnes to form tarryoils which consumed a large percentage of the olenic content of thegases. the polymerization which occurred was due prin-l cipally to thecondensing action of the acid upon the olenes ofthe gas. It has beendiscovered, however, that a large amount of polymerization loss is dueto decomposition and polymerization of the acid alkyl sulphates. Thisdecomposition oi. the acid sulphates is Aexaggerated where thetemperatures are comparatively high. In the pres- It was believed thatent invention a comparatively small loss due to polymerization of theolenes is encountered. To Y accomplish this, separate zones aremaintained in the acid absorbing tower 40 whereby the acid liquors areheld in a condition unfavorable to the polymerization of the olenes.Cold concentrated sulphuric acid (1.84v gravity) is introduced intoperatures of the liquid suillciently low to prevent polymerization ofthe olenes. The rate of reaction between concentrated sulphuric acid andthe oleiines is very rapid and the heat of reaction is quite high, sothat the liquid will soon become heated to a temperature wherepolymerization sets in if cooling is not employed. The rate of reactionbetween the olenes and the acid alkyl sulphates is very rapid, but theheat of reaction is much less than that' of sulphuric acid, so that lesscooling is required to maintain the liquor at a temperature below thepolymerization point in the zone where the alkyl acid is reacting. Thecracked oil gas containing the oleiines iscooled before it is introducedinto the tower, and this cooled gas is introduced into the zoneconsisting principally of dialkyl sulphates and acid alkyl sulphates. Inthis zone the higher boiling point olefines principally are reacted uponby the acid alkyl sulphate, and as the gas progresses upwardly throughthe absorber, the lower boiling point olenes are absorbed. At the timethe gas is passed through the mid zone in which the acid alkyl sulphatesprevail, there is a comparatively small amount of olenes in the gaswhich will be reacted upon by the concentrated sulphuric acid at thetemperatures prevailing in the absorber. In this upper zone where theconcentrated acid prevails, the last portion of the absorbable olefineshigher in the oleiine series than ethylene is absorbed and the acid isused for the purpose of removing from gasoline, the dialkyl sulphateswhich are dissolved therein as it passes upwardly through the absorberin the path of the gas. Concentrated acid acts either to dibsolve or tobreak down the dialkyl sulphates to form acid alkyl sulphates, and theacid and acid alkyl sulphates are .substantially insoluble in thegasoline; therefore by the time the gasoline has passed upwardly throughthe concentrated sulphuric acid all of the dialkyl sulphates will havebeen removed therefrom.

The cooledcracked gas is introduced into the lower portion of theabsorbing tower 40 through a pipe 38 and uniformly distributedthroughout the area of the tower bya perforated ring 39 (Fig. 2).

The cooled gas contains a considerable quantity of gasoline or similarhydrocarbons, and as the gas passes upwardly through the absorber 40 incontact with the cooling coils, the more volatile.

hydrocarbons therein are condensed and mixed with the gasoline materialwhich enters the tower 40 in a liquid state. This gasoline orhydrocarbon menstruurn being lighter than the acid, tends to moveupwardly through the tower with the gas'so that there is a movement ofgas and liquid upwardly through the tower, and a countercurrent movementof 4the sulphuric acid, the acid alkyl sulphates andthe dialkylsulphates downwardly through the tower. The mixture of sulphuric acid,acid alkyl sulphates, dialkyl sulphates, and gasoline substantially llsthe tower from top to bottom. As the gas passes through the' tower incontact with the hydrocarbon menstruum which is a high gravity gasoline,it may be that the oleflnic content oi' the gas is absorbed in thehydrocarbon mass and that the reaction between the acids and the olenesis a reaction between the oleiines absorbed in the hydrocarbon mass andthe acids. Regardless of the mechanics of the reaction, repeatedexperiments. show that the hydrocarbon liquid materially assists in aneillcient'absorption of the absorbable oleflnes in the gas and minimizesthe polymerization of the oleilnes.

arge (PbO) in 1000 parts of water.

The absorption tower 4i) is preferably cooled by means of brine and thetemperature in the tower is purposely maintained so lowpreferablybetween 32" F. and 40 F.-that substantially no ethylene is absorbed bythe acid. It is important that the low temperatures are maintained inthe lower part or the lower zone of the absorber when the raw gas isintroduced but temperatures up to 60 F. may be used in the upper zone ofthe absorber. These temperatures, however, are very suitable for theabsorption of olefines containing more than two carbon atoms so that aconsiderable` part ofthe absorbable olefiuic materials of the gases andgasoline except ethylene are absorbed by the time the gasoline and gasesleave the absorber 40. The absorption in the tower is preferably madeunderpressure because it is found that the use of pressure gives muchgreater capacity and a smoother and more efficient absorption. Pressuresof fromv75-l00 pounds per square inch give the best results forabsorption.

Gasoline and unabsorbed gases including ethylenc, pass out of the top ofthe tower 49 through pipe 46 into a trap 48 in which the condensedgasoline separates from the gases. The gasoline passes to the bottom ofthe trap through pipe 50 and the gases pass out through elbow 5| (Fig.2) and thence out of the trap through pipe 52. A certain amount ofsulphuric acid is carried over from tower 40 to trap 48 by entrainmentin the gasoline and gas and this acid separates out in trap 48 and ispermitted to flow back into the tower 40through pipe 54 connecting thebottom of trap 48 with the tower, preferably at about the fifth platefrom the top of the tower.

The gasoline passing out'of trap 48 through pipe 56 is doctor sweet andneeds only washing with water followed by a light neutralization withalkali carbonate or the like to be ready for use. A gasoline isconsidered doctor vsweet if vno vislble reaction is observed when twovolumes of gasoline are shaken'with one volume of doctor solution. Wherea visible reaction occurs between" the solution and the gasoline thetest is deemed positive, as a result of which the gasoline is consideredsour, The doctor solution to be used in the test may be made bydissolving 125 parts by weight of sodium hydroxide and 60 parts of lith-It is to be understood that the invention is not limited to the use ofany particular doctor solution. As illustrated in the drawings, pipe 56preferably connects with an agitator 58 in which the gasoline materialis washed with water to remove some acid and to improve the color afterwhich it is neutralized and drawn off through pipe 60 to storage. Thisgasoline may be used for blending with straightrun" gasoline as isusually done with cracked gasoline. It has a gravity of about 65 Baum(liquid scale), can be used alone as a motor fuel and will hold apermanently good .color and odor which is not ordinarily the case withcracked gasoline.

The construction of the absorption tower 40 is illustrated in somedetail in Fig. 2. 'I'he tower may conveniently comprise a plurality ofbubble plates 6262 of known construction, permitting the light liquidsand gases to ilow upwardly and countercurrent to the heavy acid, alkylsulphuric acid and alkyl sulphates which flow to the bottom aimons erproducts are 'forced to pass into the heavy liquids held on the upperfaces of plates 62. The heavy liquids pass downwardly through the plates82 by means of pipes 68, 68 so arranged that their upper ends arepositioned at the desired level of the heavy liquids on the upper facesof plates 62 and their lower ends dip into the layer of heavy liquidsheld on plates below the ones to which the pipes are fixed, thuslpreventing the gases and light liquids from passing up through them.Preferably a cooling coil 69 is located in each section of the tower.Brine for the cooling coils 69 is conveniently introduced through aheader 10 connected to individual coils 69 by means of,

valved connecting pipes 12. Similarly the brine may be discharged fromcoils 69 through valved drawoff pipes 14, 14 into a discharge header 16.The cooler 36 is preferably supplied with brine from header 10 throughconnection 11 (Fig. 1).

Immediately below the level at which the gases.

and gasoline are introduced into the tower through the pipe 38 is apartition or diaphragm 18 which forms the bottom of the absorption zoneof the tower. The portion of the tower below the plate 18 comprises aseparating chamber 80 which is arranged to prevent agitation of theliquid therein so that the dialkyl sulphate Will, separate from thegasoline. The heavy liquids pass down through plate 18 by pipe 82, theupper end of which maintains asuitable level of heavy liquid above plate18 so that the incoming material from ring 39 is thrown immediately intocontact with the heavysulphate liquids. However, a certain amount ofgasoline is carried down through pipe 82 by the sulphate liquids and theoutflow from the chamber 80 is so regulated that such gasoline materialhas opportunity to separate from the sulphate liquids in this chamberand ow back upwardly through plate I8 by means of pipes 84, 84 fixed to'plate 18 and extending upwardly therefrom above the readilyhydrolizable.

tower 40 are to be converted into alcohol, the.v

liquid containing them is taken off through pipe 86 and passed through amixing box 88 and a trapped pipe 90 into a hydrolizng tank 92. In thetank 92 water is added to the sulphate liquids for the purpose ofhydrolizing the alkyl sulphates to alcohols and sulphuric acid. However,

we have found that the dialkyl sulphates drawny oi from the separatorare not readily .hydrolized and consequently we prefer to introduceadditional sulphuric acid into tank 92 at the time of adding the waterfor hydrolizing purposes. 'I'he added acid either dissolves or convertsthe dialkyl sulphates to acid sulphates which are We prefer to add thewater and acid to them in the form of dilute acid which may convenientlybe introduced through pipe 94 into a vapor trap 976 whereby the diluteacid catches and lwashes back any vapors which may rise from the top oftank 92 -through pipe 98. The water or dilute acidthen passes from vaportrap 96 to the mixing box 88 through. pipe I 00. In case it is desiredto use concentrated acid to change the dialkyl sulphates to -acidsulphates such concentrated acid may be added t0 the box' 88 throughpipe |02, the water necessary for hydrolization being added through pipe94 and only so much being used as to prevent escape of vapors throughtrap.96. The acid alkyl sulphates containing more than two carbon atomsare readily hydrolized and the mixture of alcohols and weak acid fromtank 92 is drawn 'oi through a trapped pipe |04, and passed through aserlesof stills |06, |06, each having a heating coil |01 therein. Thealcohols are distilled oi fromthe acid in stills |08.

Although all but a small percentage of the alkyl sulphates formed intower 40 are recovered as su'ch and may be converted into alcohols, acertain percentage of these substances polymerize and absorb or mix withsome gasoline and sulphuricV acldtoform a diiiicultly separable mixtureor emulsion and this mixture, consisting principally of polymerizedolenesderived from the alkyl sulphates, collects as a top layer in thehydrolyzing tank 92 and is drawn off through trapped :pipe |08.

Dilute acid from stills |06 `accumulates in sump |09 and may be used inthe hydrolyzing tank 92 as above mentioned, or may be concentrated andreturned to the process.

Alcohol vapors from stills |06 pass by pipes ||0, ||0 into vapor line||2 and through line ||2 to a condenser |.4. We have found that themixture of heavy alcohols coming from con-` denser ||4 is difiicult tolter unless diluted. Water for this purpose is added preferably by apipe ||6 connecting with the condenser ||4 r on the vapor side thereof,whereby the water for diluting vpurposes assists ln condensing thealcohols. When diluted with water the mixed alcohols from condenser ||4are ltered through filter ||8 containing sawdust or the like filteringmedium.

While-we have described our improvement above in a specific manner saiddescription is not to be `consdered limiting.

It will be understood. moreover that wherever the phrase alkyl sulphate"is used herein, either in the description or claims, that both dialkyland acid alkyl sulphates are included.

It is evident that our invention avoids scrubbing the tail gases withwash oil, as is usually done because the normally Lrecoverable lightgasoline constituents are condensed at the pressures and temperaturesprevailing in condenser 36 and tower 40. It also avoids re-running allbut a small amount of the cracked condensate. Ordinarily. the entirecondensate from a cracking still is obtained in the form of. a' pressurebenzine needing to be rerun to obtain the gasoline material in a vformsuitable for lchemical treatment. According to our invention, however,only the material separating out in tank 28 needs to be rerun. It isevident also that we may run the material from the dephlegmator to thereaction or absorption'towerA 40 without separating out a pressurebenzine. -While the omission of the step of separating out the benzinewould, in our opinion, decrease the commercial eiilciency of our processand apparatus, our process would still retain many advantages if thisstep were omitted and it will be understood -that many such changes andvariations may be 1. The method of treating vapors from crackedhydrocarbon oils, which comprises condensing a pressure benzine out ofthe cracked vapors, cool- 'ng the remaining vapors, sulphating theolefins contained in the cooled material with sulfuric acid under`cooling conditions at a temperature below 60 F., and separating out adoctor sweet gasoline from the sulfuric acid residue containing alkylsulfates.

2. The method of producing a doctor sweet gasoline from vapors ofcracked hydrocarbon comprising separating out a benzine yfrom saidvapors, condensing the gasoline material in said vapors, simultaneouslysulphating said condensate and the uncondensed gases and vapors undercooling conditions at a temperature below 60 F. with concentratedsulphuric acid, and separating the gasoline from the gases and alkylsulphates.

3. The method of forming alkyl sulphates comprising passing a mixture ofsaturated and unsaturated hydrocarbon liquids, vapors and'gases incounter current relation to concentrated sulphuric acid under coolingconditions at a temperature below 60 F., and separating-the alkylsulphates from the gases and gasoline.

4. The method of making alcohols from dialkyl sulfates, which comprisesmixing the dialkyl sulfates to be treated with sulfuric acid and therebyconverting said sulfates to acid alkyl sulfates and hydrolyzing theresulting acid alkyl sulfates.

5. The method of making alcohols from dialkyl sulfates, which comprisesadding suicient dilute sulfuric acid to said sulfates to dilute and toconvert them to acid alkyl sulfates, and then hydrolyzing said acidalkyl sulfates by heating them in the presence of water.

6. `The process comprising dephlegmating cracked vapors of hydrocarbonoils, cooling the vapors and gases to a temperature of between F. and150 F. to separate out a pressure benzine, cooling the remaining vaporsand gases to condense the hydrocarbons ordinarily contained in gasolineand treating the mixture of condensate, vapors and gases withconcentrated sulphuric acid under cooling conditions below a temperatureof 60 F.

7. The process of rening cracked hydrocarbon oils, which comprisesdephlegmating such cracked oil vapors and gases, thereafter cooling thevapors and gases remaining uncondensed to condense the hydrocarbonsordinarily contained in gasoline and treating the resulting condensate,vapors and gases with concentrated sulfuric acid under coolingconditions at a temperature below 60 F. which is suiciently low toprevent substantial polymerization of the unsaturated hydrocarbonscontained in the condensate, vapors and gases being treated.

8. The process comprising dephlegmating cracked vapors and gases ofhydrocarbon oils under pressure to throw back heavy liquids and toreduce the temperature of the vapors and gases to about 520 F., reducingthe'pressure of the vapors and gases to approximately atmospheric,cooling the gases and vapors to a temperature of between 135 F. and 150F. to separate out a pressure benzine, compressing and cooling theremaining gases and vapors to condense ordinary gasoline materialtherein, and treating the mixture of condensate, vapors and gases Y withconcentrated sulphuric acid under pressure and cooling conditions at atemperature below 60 F.

9. The process of recovering low boiling point hydrocarbons from thevapors of cracked hydrocarbon oil, which comprises passing such vaporsto a condenser wherein the temperature is so controlled that vaporscondensible at temperatures below to 135 F. remain uncondensed, coolingand condensing portions of the remaining low boiling point vapors andpassing the resulting mixture of vapors and condensate at a temperaturebelow 60 F. through a contact zone in intimate contact with sulfuricacid, alkyl sulfuric acid and dialkyl sulfates.

10. The process of recovering low boiling point hydrocarbons from thevapors of cracked hydrocarbon oil, which comprises passing the vaporsthrough a condensing zone wherein the temperature is maintained suchthat vapors condensible at temperatures below 150 to 135 F. remainuncondensed, further cooling the vapors remaining uncondensed in saidcondensing zone to condense hydrocarbon constituents thereof, andpassing the condensed hydrocarbons. together with any vapors stillremaining uncondensed into contact with sulphuric acid maintained at atemperature below 50 F.

11. The process for recovering low boiling point hydrocarbons from thevapors of cracked hydrocarbon oil, which comprises passing the vaporsthrough a condensing zone wherein the temperature is maintained suchthat the vapors condensible at temperatures below 150 F. remainuncondensed, cooling the vapors leaving the condensing zone to condenseadditional quantities of hydrocarbon constituents therefrom, and passingthe condensed hydrocarbons together with any remaining uncondensedvapors into intimate contact with an acid menstruum comprising sulfuricacid, and alkyl sulfuric acid maintained at a temperature below 60 F.

12. A process of recovering low boiling point hydrocarbons from thevapors of cracked hydrocarbon oil which comprises passing such vaporsthrough a condensing zone in which a temperature is maintained such thatvapors condensible below 150 F. remain uncondensed, condensingadditional quantities of hydrocarbon vconstituents from the remainingvapors, passing the resulting condensate through an absorbing zone incontact with sulphuric acid maintained at a temperature below 50 F., andseparating the liquid hydrocarbon material from the acid treatingmedium.

13. A process of recovering low boiling point hydrocarbons from thevapors of cracked high boiling point hydrocarbons, comprising passingAthe vapors to be treated through a condensing zone wherein thetemperature is maintained at a point sufliciently high that the vaporsof gasoline leave the condensing zone uncondensed. sulphatingolen'constituents of the remaining vapors under pressure at atemperature below 50 F. in contact with the gasoline constituentscondensed from the said remaining vapors, by passing the same in contactwith sulphuric acid.

14. That step in the process of producing gasoline, which comprisestreating cracked hydrocarbon oil vapors and gas containing substantiallyno higher boiling point ,vapors than gasoline in an absorber which iscooled to a temperature below 60 F. which is suiiiciently low tocondense gasoline hydrocarbons, introducing sulphuric acid into contactand separately removing the gasoline and sulphated liquor from theabsorber. I

15. In the process of recovering olefin hydrocarbons from crackedhydrocarbon oil gas containing absorbable olefins, the steps whichcomprise passing the gas from whichthe olefins are to be recovered inintimate admixture with liquid gasoline containing unsaturatedhydrocarbons into intimate contact with a sulfuric acid absorbingmenstruum maintained at a temperature below 60 F. which is sufcientlylow to prevent substantial polymerization of the unsaturatedhydrocarbons contained in the gasoline. 16. In the process of recoveringolefin hydrocarbons from cracked hydrocarbon oil gas containingabsorbable olens, the steps which comprise passing the gas from whichthe olefins are to be recovered in intimate admixture with liquidgasoline containing saturated hydrocarbons into intimate contact with asulfuric acid absorbing menstruum maintained at a temperature below 60F. which is sufliciently low to prevent substantial polymerization ofthe unsaturated hydrocarbons contained in the gasoline.

17. The method of forming alkyl sulphates comprising passing a mixtureof saturated and unsaturated light hydrocarbon liquids, vapors andgases, containing nothing substantially heavier than the heavierfractions of gasoline,` in countercurrent relation to concentratedsulphuric acid under pressure andcooling conditions at a temperaturebelow 60 F. which is sunciently low to prevent substantialpolymerization of the unsaturated hydrocarbons contained in saidmixture, and separating alkyl sulphates from the gases and gasoline.

18. The process of treating and refining vapors and gases from apressure hydrocarbon oil cracking zone, which comprises reducing thepressure on the vapors and gases from the cracking zone to approximatelyatmospheric pressure, cooling the vapors and gases toa temperature offrom 1357 F. to 150 F., compressing and further cooling the remaininggases and vapors to condenseordinary gasoline material therein, andtreating the resulting mixture of condensate, vapors and gases withconcentrated sulfuric acid underpressure and cooling conditions at atemperature below 60 F. which is sufliciently low to prevent substantialpolymerization of the unsaturated hydrocarbons contained in thematerials'being treated.

19. The process of treating gases and vapors of cracked hydrocarbon oil,which comprises cooling the gases and vapors under superatmosphericessure to condense ordinary gasoline material contained therein, andtreating the resulting gasoline condensate with concentrated sulfuricacid under superatmospheric pressure and cooling conditions at atemperature below 60 F. which ls sufficiently low to prevent substantialpolymeri. zation of unsaturated hydrocarbons contained in the gasoline.

20. The process of producing a motor fuel and alkyl sulfates frompetroleum oils, which comprises subjecting the vapors from a petroleumoil cracking step to fractional condensation whereby a benzinedistillate is produced, subjecting'the benzine' distillate to the actionof concentrated sulfuric acid ata temperature below 60 F. which issufficiently low to prevent substantial polymerization of unsaturatedconstituents contained in thedistillate whereby portions of the olefincontent of the distillate are absorbed and converted into alkylsulfates, and separating out the resulting refined distillate as agasoline motor fuel.

- ing unsaturated hydrocarbons, which comprises 21. The process ofproducing a motor fuel and alkyl esters from cracked petroleum vapors,which comprises cooling the vapors containing the lighter fractions ofthe petroleum to produce a benzine or crude naphtha condensatecontaining substan- 5 'rated'and unsaturated hydrocarbon liquids, va-

pors and'gases for the production of sulphated hydrocarbon compounds anda motor fuel which comprises passing such mixture through a reactionchamber in contact with sulphuric acid maintained at a temperature below60 F. and of gradually increasing concentration, thereby removing fromsaid mixture th more reactive conf stituents as said mixture advancesthrough said chamber and separating the remaining hydrocarbon materialfrom the acid liquor containing the sulphated hydrocarbons.

23. The'process of producing a rened motor fuel product from an unreneddistillate containsubjecting the unrened distillate to the action of areactive acid rening agent containing sulfuric acid, intimatelycontacting the unrened distillate with said refining agent at atemperature below 40 F. which is sufficiently low to prevent substantialpolymerization of the unsaturated hydrocarbons contained in thedistillate, separating the refined distillate from the acid renlng agentand thereafter neutralizing the rened distillate.

24. The process of producing a rened motor fuel product from an unreneddistillate containing unsaturated hydrocarbons, which comprisessubjecting the unrefined distillate to the action of concentratedsulfuric acid, intimately contacting the unrefineddistillate with theconcentrated acid at a temperature of from about oil, which comprisespassing said distillate in a continuous stream through a series ofreaction zones in contact with sulphuric acid, introducing concentratedsulphuric acid into the last zone of the series and passing it throughthe said zones countercurrent to and in intimate contact with the saiddistillate, removing the treated distillate from thel last zone of,theseries and spent acid liquor from the first zone of the series,maintaining the materials in said zone under a superatmosphericpressure, and maintaining the acid and distillate in said zones at atemperature adapted to prevent substantial polymerization of the olefinconstituents contained in said distil- 70 late.

28. The method of forming diaikyl siufates from olefin'containing'materiaL which comprises intimately contacting olencontaining material with concentrated sulfuric acid in a contact zone toform acid alkyl sulfates, passing the acid alkyl sulfates into a secondzone in intimate contact with an additional quantity of olefincontaining material to convert the acid alkyl sulfates into dialkylsulfates, and maintaining a relatively low temperature in said contactzones which is sufciently low to prevent substantial polymerization ofthe olen material.

29. The method of forming dialkyl sulfates from olefin containingmaterial and sulfuric acid, which comprises intimately contacting olencontaining material with sulfuric acid in a contact zone to form acidalkyl sulfates, maintaining a sufliciently low temperature in said zoneto prevent substantial polymerization'of the olefin material,transferring the acid alkyl sulfates into a second zone of lowertemperature and intimately contacting the same with an additionalquantity of olefin containing material to convert said acid alkylsulfates into dialkyl sulfates.

30. The process of refining a cracked gasoline by the treatment thereofwith sulfuric acid, which comprises passing a mixture of crackedgasoline and liquefied normally gaseous hydrocarbons in intimate contactwith concentrated sulfuric acid in a contact zone, maintaining thegasoline mixture and sulfuric acid at a temperature below 40 F. which issufficiently low to prevent substantial polymerization of theunsaturated olefin constituents contained in said gasoline, andthereafter separating the treated gasoline from the sulphuric acid.

31. The process of refining a gasoline containing unsaturatedhydrocarbon constituents which tend to polymerize upon being treatedwith concentrated sulfuric acid, which comprises passing the gasoline tobe refined through a series of contact zones in intimate contact withconcentrated sulfuric acid, conducting the sulfuric acid through theseries of zones in a direction countercurrent to that of the gasolinebeing refined, removing the treated gasoline from the last treating zoneof the series and removing the spent acid liquor from the first treatingzone of the series, effecting prevent substantial polymerization of theunsaturated constituents contained in the gasoline, and cooling thegasoline following its intimate contact with acid in one zone and priorto its contact with acid in the next succeeding zone of the series.

32. The process of refining cracked gasoline containing polymerizableunsaturated hydrocarbon constituents with cold sulfuric acid, whichcomprises intimately contacting the gasoline and cold sulfuric acid in aplurality of separate treating zones, separating the gasoline from theacid with which it is brought in contact in each zone and passing thethus separated gasoline at a relatively low temperature to thesucceeding contact Zone, and positively cooling the gasoline during itspassage through said series of zones to a temperature sufficient tomaintain the gasoline below a temperature of 40 F. which is suiicientlylow to prevent substantial polymerization of the unsaturatedconstituents contained in the gasoline.

33. The process of refining cracked gasoline of. cold sulfuric acid landthereafter separated' from said acid, continuously introducing thegasoline to be treated into contact with the acid in each stage,continuously separating gasoline from the acid in each treating stageand conducting the resulting separated gasoline into the next succeedingtreating stage, and maintaining the temperature of the gasoline and acidin each treating stage below a. temperature of F. which is suicientlylow to prevent substantial polymerization of the unsaturatedconstituents contained in the gasoline being treated.

34. The process denedby claim 33 in which the gasoline and sulfuric acidbrought into intimate contact with each other in each zone aremaintained under a substantial superatmospheric pressure.

35. 'Ihe process of refining a doctor sour gasoline containingsubstantial proportions of unsaturated hydrocarbon constituents, whichcomprises chilling the gasoline to be treated to a relatively lowtemperature and passing it into a treating zone in contact with coldsulfuric acid, agitating the gasoline with the acid in said zone tobring the gasoline and acid into intimate contact with each other,separating the gasoline from the resulting acid liquor and passing. thethus treated gasoline into a succeeding treating zone in contact with abody of cold concentrated sulfuric acid, agitating the gasoline with theacid in said succeeding zone to thereby bring the gasoline and acid intointimate contact with each other, separating the treated gasoline fromthe acid following said contact, neutralizing the thus treated gasoline,and maintaining a temperature in said acid contact zones below atemperature of 60 F. which is sufficiently low to prevent substantialpolymerization of the unsaturated hydrocarbon constituents contained insaid gasoline.

36. The process of producing a rened motor fuel from an unrei'lned oilcontaining unsaturated hydrocarbons which are polymerizable withconcentrated sulfuric acid at the temperatures employed in the usualsulfuric acid treatment and sulfur compounds which tend to make theunrefined oil sour, which comprises cooling the unrened oil to betreated and concentrated sulfurie acid to a temperature below that atwhich the resulting cold concentrated sulfuric acid will causesubstantial polymerization of the said unsaturated hydrocarbons,thereafter intimately mingling the cooled acid and the cooled unreiinedoil to treat and refine the latter at relatively low temperatureswhereby substantial polymerization of said unsaturated hydrocarbons isprevented `and the excess sulfur compounds removed from thev oil, andseparating the reiined'oil from the acid residue.

37. The process defined by claim 36 in which the cooled oil andconcentrated acidl are intimately mingled at a temperature below 40 F.and in which conditions are controlled to prevent a substantial rise inthe temperature by the heat evolved from the reaction between the oiland the acid.

38. The process-defined by claim 33 in 'which the conditions of intimatecontact between the` gasoline and the cold sulfuric acid are socontrolled as to prevent a substantial rise in the temperature in eachstage by the heat evolved from the reaction between the gasoline and theacid. Y

ROBERT M. ISHAM. HENRY N. LYONS.

asv

CERTIFICATE oF coRREcTIoN.

` vPatent No. 2,-1)45,O25. 1 'January 219419599v ROBERT H. IsHAR, ET AL.It is hereby certified that error appears inthe printed specification ofthe above numberedlpatent requiring oorrectionas follows: Page 5, secondcolumn, line 66, claim 2T, for the word "zone" read `zones; and thatthe-'said 'Letters Patent should be read with this correction thereinthat the same ma.;r conform to'fthe record of theoase inthe PatentOffice.'

signed and seals@ this ist day of August, A. D, 1959.

Henry Van .lursdelle (Seal) l Acting Commissioner of `Patents.

